Yes, I used them once a while ago.
Negatives were a) the hotel was pretty shitty and b) although the website stated quite clearly I could cancel the booking up to 24 hours beforehand, when confirmation of my booking arrived it said it was none-cancelable. I queried this and they basically weren't interested. They are based in Barcelona so arguing with them to get your money back would have been tricky. As it happened I didn't need to cancel but I wasn't happy about being lied to. On a more positive note, they were in no rush to kick me out when my time was up, I expect I could have stayed all night if I'd wanted to.